Referring to FIG. 1, a conventional T-shape socket wrench has a head 1 and a handle 2 running radially through two sides of the head 1 to be grasped by a user to exert forces. There is a square coupling portion 3 beneath the head 1. The coupling portion 3 has a housing cavity 4 on one side wall to hold a spring 5 and a steel ball 6. The steel ball 6 is jutting outwards under the elastic force of the spring 5 to be wedged in a socket (not shown in the drawing) of a matching profile. By turning the handle 2 the head 1 can drive the coupling portion 3 to turn the socket to drive a work piece (such as a bolt or nut) to rotate.
In practice the handle 2 runs through the head 1 on the left side and right side at a selected length. The handle 2 is fixedly fastened to the head 1 and cannot be removed. Hence a larger operation space is required to use the T-shape socket wrench. Carrying is not convenient and practicality suffers.
Moreover, using a T-shape socket wrench to drive a socket of one specification in dimension is not economic effective.